Diffusing-screen



M. MAYER AND T. YEO. DIFFUSING SCREEN.

APPLICATION FILED OCT. 30. l9l9.

Patented Dec. 7,19%.

%' anuewfow e0 W g my. 171 Max/Ila 720]]? as UNITED STATES PATENT OFFICE.

" MAX MAYER, OF FORT LEE, AND THOMAS YEO, OF UNION HILL, NEW JERSEY,

ASSIGNORS TO M. (T. WOHL TION OF NEW YORK.

& 00., OF BROOKLYN, NEW YORK, A CORPORA- DIFFUSING-SCREEN.

Specification of Letters Patent.

Patented Dec. '7, 1920.

Application filed October 30, 1919. Serial No. 334,596.

To all whom it may concern:

Be it known that we, MAX MAYER, a citizen of the United States, and resident of the town of Fort Lee, in the county of Bergen and State of New Jersey, and THoMAs Yno, a citizen of the Dominion of Canada, and a resident of the town of Union Hill, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Diffusing-Screens, of which the following is a specification.

This invention relates to improvements in screens adapted for use as light diffusing devices in connection with sources of artificial r light for photographic purposes and particularly to that class of such devices, in whicha sheet of pliable material, as spun glass or the like, is used as diffusing medium.

It is the object of the present invention, to provide an improved device of this character, comprising a frame forv holding the diffusing material securely and permitting its removal and facilitating its renewal without injury to either the frame, or the diffusing material.

W'ith these and other objects in'view the invention consists in certain novel details of construction and arrangement of parts,

" 'hereinafter described and shown and illustrated in the accompanying; drawings,'made part of this specification, in which: a

Figure I is a front elevation, showing the upper half of a diffusing screen embodying the invention.

Fig. II is a vertical section through Fig. I on the line A-A.

Fig. III is an enlarged front elevation showing in detail a corner of the diffusing screen shown in Figs. I and II.

Fig. IV. is a sectional side elevation of Fig. III.

Fig. V. is a front elevation of the lower half of a diffusing screen provided with. a modification of the clamping means.

Fig. VI. is a vertical section through Fig. V taken on the line 13-13.

Fig; VII. is an enlarged front elevation,

The difi'using screen consists of a sheet 1 made of fine spun strands 1 of non-combustible and tanslucent material, preferably glass, disposed parallel to each other, forming the warp of the sheet. These strands are supported and retained in position by spaced metallic cross wires 2 which are woven into the sheet, forming its woof, and serve to stiffen it. A rectangular sheet of diffusing material so constructed, is preferably held in a frame of suitable size formed by shaped moldings of metal, either pressed from a solid sheet, or mitered at the corners and joined by welding or any other suitable process, As shown in Figs. I to IV, the diffuser frame consists of a base molding 3 consisting of a flat portion and a ledge formed thereon by two bends 8' and 8 along the opening of the frame. The cover section 4 of the frame is formed to fit the base section having a similar ledge consisting of bends 4 and 4". The diffusing sheet 1 is held between. base section 3 and cover 4 being pressed to assume a bent shape between their ledges Z. -3 and 4 -4 The base and cover sections are clamped against each other to firmly hold sheet 1 by means of the U-shaped channels 5 which are preferably resilient and held in place near the corners of the frame by pins or clench rivets 6 extending through apertures in sections 3, 4, and channels 5..

In Figs. J to VIII a modification of the holding frame is shown. In this construction the base section 7 of the frame is also provided with ledges 7" and 7 surrounding the opening of the frame, but the outward edges of this section are formed by a reverse bend into a U shape at 7 and 7 The cover section 8 of this, frame corresponds in shape to that of cover section 4, but its outer dimensions are such that the cover section can be inserted into base section 7, itsouter edges passing the inwardly turned edges of 7 At various places of the cover 8 oscillating latch bars 9 preferably made from resilient ma terial are fastened by means of pins 10 which when opened are in a position as shown at 9 Fig. V and when closed rest with their outer faces against the inner face of ledge 7F and thereby press section 8 against the diffusing sheet, lying between this section and base section 7.

The operation of inserting and removing a sheet of diffusing material is easily accomplished in either construction by opening the clamping means, removing the'pins 6 and channels 5 from the frame shown in Figs. I to IV or turning the latch bars 9 into the position shown at 9 when using a frame as illustrated in Figs. V to VIII. The cover and base sections may then be separated, a diffusing sheet placed fiat upon the base section and pressed to take a bent shape along its edges by pressing the cover section against the base section, which effects a stretching of the body part of the sheet by tying it over the bends 3 (or 7), and replacing the clamping means.

As the diffusing medium must be very tightly fastened to the frame along its edges, it was customary heretofore to permanently fasten the difiusing sheet into a frame and abandon the frame with a worn diffusing sheet.

By the present invention this difficulty is overcome by means of the bend producing an indentation in the diffusing sheet along the inner 'edges of the frame which prevent a slipping of the sheet in the frame and which tend to stretch the sheet while it is being inserted into the frame. The invention also makes it possible to use diffusing sheets of different colors in the same frame.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is: i

1. In a device of the kind described, a frame including means to stretch and clamp a sheet of pliable material, formed by bars permanently joined at their ends, said frames being separable along a plane parallel to said sheet and clamping means concealed within the outlines of said bars to give an unobstructed polygonal. outline to said frame.

2. In a device of the kind described, a frame including means to stretch and clamp a sheet of pliable material, separable along a plane parallel to said sheet, said frame and said clamping means consisting of shaped fiat metallic bars, said clamping means forming the front and rear sides of said device into extended parallel planes.

3. In a device of the kind described a sheet of pliable material, a frame formed by bars permanently joined at their ends leaning against one side of said sheet, pressing means leaning against its opposite side and resilient clamping bars forming alining guides at the outer faces of said frame adapted to clamp said sheet between said pressing means and saidframe.

4:. In a device of the kind described 'a sheet of; pliable material, aframe formed by bars permanently joined at their ends leaning against one side ofsaid sheet, press ing meansrleaning against its lOppOSltG-FSKle and clamping bars lying flat against said pressing means and said frame on opposite sides to form parallel guides at the outer edges of said device to clamp said sheet between said pressing means and said frame.

5. In a device of the kind described a sheet of pliable material, a pair of frames leaning against opposite faces of saidsheet, means on said framescooperating with each other, to deflectnnder pressure a margin completely surrounding said sheet and-resilient clamping bars lying flat against opposite faces of said frames removably fastened thereto.

6. In a device of the kind described a sheet of pliable material, a frame supporting the border of said sheet on opposite faces and including means to produce a deformation of said border completely surrounding said sheet and separable clamping means adapted to hold said sheet within said frame in deformed position and forming a rectangular outline on said device.

In a device of the kind described, a sheet of pliable material, a frame consisting of shaped metal moldings permanently joined at their ends supporting the border of said sheet on opposite faces and including means to produce a deformation of said border under pressure and clamping latches concealed within the front and rear faces of said moldings, adapted to hold said sheet rigidly within said frame in deformed pos 1t1on.

8. In a device of the kind described a sheet of pliable material a frame surrounding the edges of'said sheet and leaning against one of its faces, pressing means leaning against the opposite face of said sheet and clamping means movably fastened to said pressing means, adapted to cooperate with means on said frame to hold said pressing means in .place on said frame.

9. In a device of the kind described, a sheet of pliable material, a frame consisting of a single sheet-metal molding leaning against one face of said sheet along its border, a ledge along the face-opening of said frame, and pressing means consisting of a similarly formed sheet-metal molding adapted to stretch said sheet and clamping means within the outlines of said moldings to hold said sheet within said frame.

10. A diffusing screen consisting of a sheet of pliable material, interposed between a pair of matched sheet-metal moldings forming a frame, and having an offset in transverse section adapted to deform said sheet under-pressure and clampingmeans to press said moldings againstsai'd sheet inclosed within the outlines ,o'frsaid frame.

MA :rHoMAs. .YEO, 

